Dirac semimetal phase in hexagonal LiZnBi

Based on first-principles calculations, we find that LiZnBi, a metallic hexagonal $ABC$ compound, has a pair of three-dimensional Dirac nodes and exhibits nontrivial topological properties under proper strain configurations. The nontrivial topological nature of the strained LiZnBi is directly demonstrated by calculating its ${\mathbb{Z}}_{2}$ index and the surface states. The low-energy states are shown to be sensitive to strain configurations, and we propose that these nontrivial topological properties can be observed under compressive in-plane strain in experiments. The finding of the Dirac semimetal phase in LiZnBi may intrigue further research on the topological properties of hexagonal $ABC$ materials and promote new practical applications.